Models and definitions of quality of life

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1 Models and definitions of quality of life PoCoG Quality of Life Webinar 20 th August 2015 Dan Costa (we will commence at 5 past the hour)

2 Does [insert intervention] improve quality of life? What does this mean?

3 PART I How is quality of life defined?

4 Where to look 1. Books 2. Research articles (empirical and theoretical) 3. Models 4. Health organisations

5 1. Books

6 Quality of life (QoL) is an ill-defined term... most people, in the Western world at least, are familiar with the expression quality of life and have an intuitive understanding of what it comprises. 1. BOOKS

7 Concepts of health often lack clarity... The term quality of life also has many meanings. 1. BOOKS

8 a vague and ethereal entity, something that many people talk about, but which nobody clearly knows what to do about. 1. BOOKS

9 QOL in the Benthamite tradition is essentially contentment, whereas QOL in the Aristotelian sense in a meaningful and fulfilling life. 1. BOOKS

10 2. Research articles (empirical and theoretical)

11 a kind of umbrella under which are placed many different indexes dealing with whatever the user wants to focus on. Feinstein, A.R. (1987). Clinimetric perspectives. Journal of Chronic Diseases, 40, ARTICLES

12 but seriously Quality of life in clinical medicine represents the functional effect of an illness and its consequent therapy upon a patient, as perceived by the patient. Schipper, H., Clinch, J.J., & Olweny, C.L.M. (1996). Quality of life studies: Definitions and conceptual issues. In: Spilker B (ed). Quality of life and pharmacoeconomics in clinical trials (2nd ed). Philadelphia: Lippincott-Raven Publishers. 2. ARTICLES

13 HRQOL refers to the extent to which one s usual or expected physical, emotional, and social wellbeing are affected by a medical condition or its treatment. Cella, D. (1995). Measuring quality of life in palliative care. Seminars in Oncology, 22, ARTICLES

14 HRQOL is a multidimensional construct encompassing perceptions of both positive and negative aspects of dimensions, such as physical, emotional, social, and cognitive functions, as well as the negative aspects of somatic discomfort and other symptoms produced by a disease or its treatment. Osoba, D. (1994). Lessons learned from measuring healthrelated quality of life in oncology. Journal of Clinical Oncology, 12(3), ARTICLES

15 the functional effect of an illness and its consequent therapy upon a patient, as perceived by the patient. the extent to which one s usual or expected physical, emotional, and social well-being are affected by a medical condition or its treatment. a multidimensional construct encompassing perceptions of both positive and negative aspects of dimensions, such as physical, emotional, social, and cognitive functions, as well as the negative aspects of somatic discomfort and other symptoms produced by a disease or its treatment. 2. ARTICLES

16 3. Models

17 World Health Organization (2002). Towards a Common Language for Functioning, Disability and Health. Geneva: WHO. 3. MODELS

18 Wilson, I.B., & Cleary, P.D. (1995) Linking clinical variables with health-related quality of life: a conceptual model of patient outcomes. Journal of the American Medical Association, 273(1), MODELS

19 Wilson and Cleary Page 60 The concept of quality of life is distinct from health, though related to it. Economic, political, cultural, and spiritual factors may affect overall quality of life, but are generally not considered to fall under the purview of physicians and health care systems. Health status and HRQL can refer to different concepts, but in this article we use the terms interchangeably. 3. MODELS

20 Elements vs. determinants of quality of life Ferrans, C.E., Zerwic, J.J., WIlbur, J.E., & Larson, J.L. (2005). Conceptual model of health-related quality of life. Journal of Nursing Scholarship, 37(4), So what are the elements and what are the determinants? It depends on the definition. Costa, D.S.J, & King, M.T. (2013). Conceptual, classification or causal: models of health status and health-related quality of life. Expert Reviews in Pharmacoeconomic Outcomes Research, 13(5), Costa, D.S.J. (2015). Reflective, causal, and composite indicators of quality of life: a conceptual or an empirical distinction? Quality of Life Research, 9, MODELS

21 Both the multitude and persons of refinement... conceive the good life or doing well to be the same thing as being happy. But what constitutes happiness is a matter of dispute... Some say one thing and some say another, indeed very often the same man says different things at different times: when he falls sick he thinks health is happiness, when he is poor, wealth. Aristotle, Nichomachean Ethics 3. MODELS

22 4. Health organisations

23 an individual s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns. It is a broad ranging concept affected in a complex way by the person s physical health, psychological state, personal beliefs, social relationships and their relationship to salient features of their environment. 4. HEALTH ORGANISATIONS

24 HRQL is a multidomain concept that represents the patient s general perception of the effect of illness and treatment on physical, psychological, and social aspects of life. A PRO [patient-reported outcome] is any report of the status of a patient s health condition that comes directly from the patient, without interpretation of the patient s response by a clinician or anyone else. 4. HEALTH ORGANISATIONS

25 Other thoughts Quality of life vs. unmet needs HRQoL questionnaires: perceived direct impact of illness and its treatment. Needs questionnaires: extent to which consequent needs for supportive care are currently met. Conceptually and empirically similar? Colagiuri, B., King, M. T., Butow, P. N., McGrane, J. A., Luckett, T., Price, M. A., & Birney, D. P. (2012). A comparison of the FACT-G and the supportive care needs survey (SCNS) in women with ovarian cancer: Unidimensionality of constructs. Quality of Life Research, 21,

26 Working definition Quality of life: what quality of life instruments measure

27 PART II How is quality of life assessed?

28 Method of assessment 1. Descriptive questionnaires 2. Single item 3. Utility instruments

29 1. Descriptive questionnaires

30 1. I have a lack of energy 15. I feel sad 2. I have nausea 3. Because of my physical condition, I have trouble meeting the needs of my family 4. I have pain 18. I feel nervous 5. I am bothered by side effects of treatment 19. I worry about dying 16. I am satisfied with how I am coping with my illness 17. I am losing hope in the fight against my illness 6. I feel ill 20. I worry that my condition will get worse 7. I am forced to spend time in bed 21. I am able to work (include work at home) 8. I feel close to my friends 22. My work (include work at home) is fulfilling 9. I get emotional support from my family 23. I am able to enjoy my life 10. I get support from my friends 24. I have accepted my illness 11. My family has accepted my illness 25. I am sleeping well 12. I am satisfied with family communication about my illness 26. I am enjoying the things I usually do for fun 13. I feel close to my partner (or the person who is 27. I am content with the quality of my life right my main support) now 14. I am satisfied with my sex life FACT-G 1. DESCRIPTIVE QUESTIONNAIRES

31 LSQ IBCSG SF-36 MHIQ FACT-G LTQL QLI PROSQOLI NHP POS FLIC SCI RSCL QLQ-C30 SIP et cetera MQOL DLQI COOP SF-12 TQ GIQLI ASC MDASI QLACS AQEL WHOQOL GLQ-8 UBQ-C SIP PC-QoL MSAS 1. DESCRIPTIVE QUESTIONNAIRES

32 Reflective or formative? Wind down Sleep Anxiety Agitated Can t relax Daily activities Quality of life Work Touchy Reflective indicators comprise a scale Elements or determinants? Formative (or, more specifically, causal or composite) indicators comprise an index 1. DESCRIPTIVE QUESTIONNAIRES

33 2. Single item

34 How would you rate your overall quality of life? 2. SINGLE ITEM

35 Advantages Easy for respondents to answer Low burden Does not (explicitly) confound elements and determinants 2. SINGLE ITEM

36 How do single items perform compared to multi-item scales? Quite nicely High test-retest reliability Moderate-high responsiveness de Boer, A.G.E.M., van Lanschot, J.J.B., Stalmeier, P.F.M., van Sandick, J.W., Hulscher, J.B.F., de Haes, J.C.J.M., & Sprangers, M.A.G. (2004). Is a single-item visual analogue scale as valid, reliable and responsive as multi-item scales in measuring quality of life? Quality of Life Research, 13, SINGLE ITEM

37 Problems Interpretation and measurement error What are respondents thinking when they answer the question? SINGLE ITEM

38 Problems Even with haemorrhoids I think my quality of life is pretty good. That could be interpreted broadly to include everything or it could relate only to the cancer. Seeing as everything else I ve said is related to the cancer I should be consistent and relate this to the cancer. My life is really, really good. Except I m renovating 2. SINGLE ITEM

39 3. Utility instruments

40 Weighted by preferences i.e., Descriptive instruments ask how severe or how often? Utility instruments do the same but apply a preference weighting 3. UTILITY INSTRUMENTS

41 Quantity vs. quality Quantity of life Quality of life 10 years 70% Survival time 30% 5 years Quality of life Treatment 1 Treatment 2 3. UTILITY INSTRUMENTS

42 Multi-attribute utility instruments Administer a small number of items (like a descriptive instrument) to patients in a clinical trial The items have previously been valued by a large sample so that each item has a utility weight General population usually provides valuations 3. UTILITY INSTRUMENTS

43 e.g., EQ-5D Health state = particular combination of levels After valuation, each item level gets a utility decrement weight 3. UTILITY INSTRUMENTS

44 EQ-5D Mobility Self-care Usual activities 3 5 = 243 health states Pain/ discomfort Anxiety Quality of life = aggregate of effects Are these items sensitive enough? 3. UTILITY INSTRUMENTS

45 Problem What items go in? Who decides and using what criteria? Implicit definition of quality of life: patient perception of the effects of illness and treatment as modified by various factors chosen by a specific research team and valued by a large number of other people, most of whom have not experienced the illness. 3. UTILITY INSTRUMENTS

46 Solution? What about an assessment of the effects of illness and treatment weighted by what s important to the patient? the value assigned to duration of life as modified by the impairment, functional states, perception and social opportunities that are influenced by disease, injury, treatment, or policy How do we assess this? Ask the patient to list what is important to them, then assign weight, then aggregate? OR

47 How would you rate your overall quality of life?

48 What value does the term quality of life have? As an outcome of a clinical trial? As an item in a questionnaire? As an umbrella term for patient-reported outcome measures? As a name for a field of research?

Title of measure: Functional Assessment of Cancer Therapy-Brain (FACT-Br)

Title of measure: Functional Assessment of Cancer Therapy-Brain (FACT-Br) This summary was last revised 5 October 2010. Brief overview: The Functional Assessment of Cancer Therapy-Brain (FACT-Br) is a